Rare-earth magnets and Japanese precision-reducer makers carry the robotics basket while high-beta software lags in the rate selloff.

USA Rare Earth (USAR) led the robotics basket, up 8.3% to $23.55, with MP Materials (MP +6.6%, $60.84) alongside, as the permanent-magnet chokepoint drew a sector bid amid China's rare-earth export-control squeeze. For humanoids and industrial robots this is the most direct chokepoint of all: every joint actuator runs on a NdFeB-magnet servomotor, and domestic magnet capacity — USAR's Stillwater, Oklahoma plant and MP's Independence facility — is the supply story. No single dated catalyst drove June 17; the move extends a structural re-rating on the onshoring thesis.

The other chokepoint that rallied was precision reduction gearing — the strain-wave and cycloidal reducers that set a robot's repeatability. Harmonic Drive Systems jumped about 12% in its June 17 Tokyo session (its US line, HSYDF, marked $48.36), and Nabtesco rose roughly 4% (NCTKY), as the humanoid-actuator supply chain caught a strong bid. These two Japanese makers effectively gate high-precision reducer supply for the entire industry — a physical chokepoint that no amount of robotics software can route around.

Unity Software (U) was the basket's worst at −5.7% to $26.47. There was no fresh company catalyst; the high-beta, pre-profit software name sold off with the broad tape after the Fed's hawkish dot plot, compounded by a standing overhang from AI world-model tools (such as Alphabet's Project Genie) that threaten the traditional game-engine moat. In the robotics frame, Unity sits at the simulation and digital-twin chokepoint — the synthetic environments used to train embodied-AI policies before they reach hardware. Amprius (AMPX −3.2%, $15.00) also lagged.

Tesla's (TSLA) Q2 (July 22) and the estimated Optimus Gen 3 reveal and low-volume production start (summer 2026) are the marquee humanoid catalysts ahead. Nabtesco reports first-half results on July 31 and Harmonic Drive its quarter in early-to-mid August — direct reads on reducer order books. MP Materials (July 30) and USA Rare Earth (August 10) report Q2, the magnet-supply checkpoints for the actuator chokepoint.